Diffusion‐Weighted MRI‐Based Virtual Elastography and Shear‐Wave Elastography for the Assessment of Breast Lesions

Background Diffusion‐weighted imaging (DWI)‐based virtual MR elastography (DWI‐vMRE) in the assessment of breast lesions is still in the research stage. Purpose To investigate the usefulness of elasticity values on DWI‐vMRE in the evaluation of breast lesions, and the correlation with the values calculated from shear‐wave elastography (SWE). Study Type Prospective. Population/Subjects 153 patients (mean age ± standard deviation: 55 ± 12 years) with 153 pathological confirmed breast lesions (24 benign and 129 malignant lesions). Field Strength/Sequence 1.5‐T MRI, multi‐ b readout segmented echo planar imaging ( b ‐values of 0, 200, 800, and 1000 sec/mm 2 ). Assessment For DWI‐vMRE assessment, lesions were manually segmented using apparent diffusion coefficient (ADC 0–1000 ) map, then the region of interests were copied to the map of shifted‐ADC (sADC 200–800 , sADC 200–1500 ). For SWE assessment, the shear modulus of the lesions was measured by US elastic modulus (μ USE ). Intraclass/interclass kappa coefficients were calculated to measure the consistency. Statistical Tests Pearson's correlation was used to assess the relationship between sADC and μ USE . A receiver operating characteristic analysis with the area under the curve (AUC) was performed to compare the diagnostic accuracy between benign and malignant breast lesions of sADC and μ USE . A P value <0.05 was considered statistically significant. Results There were significant differences between benign and malignant breast lesions of μ USE (24.17 ± 10.64 vs. 37.20 ± 12.61), sADC 200–800 (1.38 ± 0.31 vs. 0.97 ± 0.18 × 10 −3 mm 2 /sec), and sADC 200–1500 (1.14 ± 0.30 vs. 0.78 ± 0.13 × 10 −3 mm 2 /sec). In all breast lesions, a moderate but significant correlation was observed between μ USE and sADC 200–800 /sADC 200–1500 ( r = −0.49/−0.44). AUC values to differentiate benign from malignant lesions were as follows: μ USE , 0.78; sADC 200–800 , 0.89; sADC 200–1500 , 0.89. Data Conclusions Both SWE and DWI‐vMRE could be used for the differentiation of benign versus malignant breast lesions. Furthermore, DWI‐vMRE with the use of sADC show relatively higher AUC values than SWE. Level of Evidence 4 Technical Efficacy Stage 2